Microbiological studies on soils fertilized with pig slurry

The number of bacteria participating in transforming carbon, nitrogen, sulphur and phosphate compounds and the number of actinomycetes, filamentous fungi and yeasts in soil fertilized with pig slurry was studied. The following types of soil were considered: — the arable layer of acid brown and black soil — the turf layer of mineral — marsh soil The following three areas were separated for estimating the influence of pig slurry on soil bacteria: 1- untreated with pig slurry 2- fertilized with slurry every 2-3 years (1975-1990) 3- fertilized with slurry every year (1975-1991) These areas were in Strzebielin Morski, in Gdańsk region. As a rule, all microorganisms occured in lower amounts in acidic brown soil, and in higher amounts in black and mineral - marsh soils. The counts of microorganisms in the soil fertilized with pig slurry were higher compared to these in untreated soils. The frequency of fertilization had no effect on the microorganism counts.